Ventilating system for an internal combustion engine



D. K. BADERTSCHER ET AL 2,

VENTILATING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE A ril s, 1958 FiledNov. 19, 1956 m. n m

M/crmv 5. 80L 2 BY i I atent Ofiice 2,829,629 Patented Apr, 8, 1958VENTILATHQG SYSTEM FOR AN INTERNAL COMBUSTION ENGINE ApplicationNovember 19, 1956, Serial No. 623,111 8Claims. (Cl. 123-419) Theinvention relates to a ventilating system for removal of harmful andcorrosive vapors from the crankcase of an internal combustion engine andparticularly of the type suitable for operation while submergedternporarily under water.

In an engine of the type suitable for under water operation, the variouscomponents such as the distributor, spark plugs, fuel pump, etc., arefabricated in such a way as to be housed in water-tight receptacles andmost of these components need air for some reason and consequently, mustbe provided with a ventilating system.

The general object of the invention is to provide an improved air routearrangement in a ventilating system for an internal combustion engine.

A specific object is to provide an improved valving arrangement in anengine ventilating system wherein a combination valve is housed in asingle casting and operated with a single control element.

A further object is to provide a relief valve with appropriatepassageways circumventing the main control valve for relieving excessivecrankcase back pressure when necessary to avoid possible fracture ofsealing gaskets where provided.

Other objects and advantages will be apparent from the ensuingspecification and appended drawing in which:

Figure 1 is a schematic view of an engine employing the ventilatingsystem;

Figure 2 is a plan view of the combination control valve taken generallyon the line 2-2 of Figure 1;

Figure 3 is a fragmentary sectional view taken on the line 3-3 of Figure2;

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure2; and

Figure 5 is a detail sectional View of the crankcase ventilation controlvalve.

Referring to Figure l, we have shown schematically a typical V-typeinternal combustion engine having a crankcase A to theunderside of whichis secured the oil storage pan B. The cylinder castings C and D happento be of the removable type secured to the crankcase casting withsuitable sealing means. The cylinder castings, of course, house theconventional pistons (not shown) which are actuated by the conventionalcrankshaft (not shown) mounted within the crankcase casting in aconventional manner. In this particular engine overhead type valves (notshown) are employed and these are housed within the cylinder heads C andD covered by covers E and F, the combustion chambers being also locatedwithin the cylinder heads. The combustion chambers are fed through theintake manifold ducts G and H which emanate from the intake manifold I.A conventional carburetor (not shown) would be positioned between theintake manifold and the air cleaner I for atomizing the fuel beforeentering the intake manifold preparatory to distribution to the variouscylinders.

In an engine which is not intended for underwater operation, thedistributor and fuel pump would incorporate small vent holes, however,the instant engine employs in its ignition system a distributor K and afuel pump L, both of which are provided with appropriate means foraccepting the tubing so as to be included in the air route of theventilating system.

The ventilating system is preferably accomplished in part by the use ofsections of tubing extending between the various parts which needventing and it will be understood that the tubing as shown in Figure 1is greatly oversized in proportion to the engine size as shown and itwill be understood that the actual size of the tubing sections need onlybe such as to provide the desired venting as needed. The system may besaid to commence at the air cleaner with tubing sections 10 and 11leading from a common fitting 12 which is in open communication withfiltered air of the air cleaner. The section It) terminates at thedistributor K and section 13 leaves the distributor and leads to theinlet passage 14 in the combination valve assembly which may beidentified generally with the letter M. The passage 14, with the valvecore 15 in. its normally opened position as shown in Figures 3 and 4,communicates with outlet passage 16 into tubing section 17 whichleadsinto the intake manifold, first passing through the valve assemblywhich may be generally identified with the letter N.

Section 11 leads from the air cleaner into passage 18 (see Figure 3) ofthe combination valve assembly and, with the valve core in openposition, communicates with passage 19 which opens into the interior ofthe crankcase. The valve body which may be identified by the numeral 20has an externally threaded fitting portion 21 which is threaded into theboss 22 which is formed on the timing gear cover which communicates withthe crankcase.

From the crankcase casting a section of tubing 23 leads to the interiorof the cylinder head cover F from whence the discharge passage 24 opensinto the tubing section 13. it will be understood that there is a tubingsection 23 to accommodate each bank of cylinders, the tubing sectionleading to the cylinder head cover E not being shown. A section oftubing 25 leads from the discharge passage 26 of the cylinder head coverE to the inlet passage 27 in the combination valve body, said latterpassage intersecting with the passage 14 previously referred to. Asection of tubing 28 leads from valve passage 29 to the fuel pump Lwhich represents a dead end for this particular tubing section. It isnot necessary to maintain a continuous run in the air route through thefuel pump. This is due to the fact that there are only air pulsationscaused by the stroke of the fuel pump diaphragm.

Viewing Figure 2, it will be noted that the passages in the valve bodyas shown in Figure 3 lie in a plane which is spaced from the plane inwhich the passages as shown in Figure 4 lie. The valve body has a valveseat in the form of a conical bore 30 extending therethrough which boreintersects the transfer passages 31 and 32 and the valve core 15 hasdiametn'c bores 33 and 34 which are in registry with the respectivetransfer passages 31 and 32 at a common position of the valve corewithin the bore. Thus, when the valve core is rotated to open position,both of the core bores 33 and 34 are in registry with the respectivetransfer passages simultaneously and likewise when the valve core isrotated to closed position, the transfer passages 31 and 32 are closedoif simultaneously.

In Figure 2, there is shown a preferred form of valve control consistingof a Bowden wire 35 operable within a suitable sheathing 36 which may besupported near the control knob 37 by means of any suitable stationarysupport 38. The end of the sheathing adjacent the valve assembly isanchored within the loop 39 formed at the end of the arm 41a which maybe integral with the bracket 41. The bracket is secured to the end faceof the valve body as by means of bolts 42 and a pair of outwardly turnedears 43 and 44 on the bracket serve as stops when rotating the valvecore to open or closed position. The valve core has a diametricallyreduced end portion 45- projecting exteriorly of the valve body and oneend of link 46 is secured to the end of the valve core. A pin 47 iscarried on the opposite end of the link rotatively relative thereto, theend of the Bowden wire being anchored to the pin as by means of setscrew 48. The bracket has an extension 49 with an outwardly turned ear tand the opposite ends of tension spring 51 are anchored respectively tothe link 46 and the car 50 for assisting in returning the valve core toopen position (with the link engaging. ear 44). Thus when it is desiredto close the valve, the knob 37 is pulled outwardly causing the link toswing over against car 43 (the position shown in Figure 2). valve core aspring 73 exerts tension on the pin 74 to retain the valve core (whichis of the tapered or conical type to conform to the valve seat) in thevalve body.

Operation In operation, assuming that the engine is functioning undernormal conditions without being submerged, then the valve core is in itsnormally open position as shown in Figures 3 and 4 wherein link 46 isengaged with ear 44 and the overall air route from the air cleaner tothe intake manifold is open as a result of the transfer passages 31 and32 being open. Then the atmospheric air travels through the air cleaneras indicated by the arrow 4t and thence through the tubingsections 1tand 11. The air flow is induced as a result of the suction condition (orsubatrnospheric pressure condition) Within the intake manifold and theair travels through tubing 11, passage 18, transfer passage 31, valvecore bore 33,

outlet passage 19 into the interior of the crankcase where theaccumulation of blow-by gases is picked up and discharged as desiredthrough the tubing sections 23 into the interiors of the respectivecylinder head covers E and F, then through discharge passages 24 and 26into tubing sections 13 and 25, then through passages 27 and 14,transfer passage 32, valve core bore 34, passage 16, into tubing 17 andon into the intake manifold through the regulating valve N. The airwhich flows through tubing it travels through the interior of thedistributor casing and on through tubing 13 where it merges with the airbeing expelled out of discharge passage 24. The air traveling throughtubing 11 and valve passage 18 is exposed to the passage 29 which leadsthrough tubing 28 into the fuel pump L, the passage 28 being a dead endone.

During periods in which a high vacuum condition exists within the intakemanifold, such as would tend to induce a high. volume flow so as tointerfere with the proper operation of the carburetor, it is necessaryto restrict air flow through tubing 17 and this is accomplished by meansof the regulating valve N which is conventional. The tubing 17 leadsinto the valve fitting 61 and the tubing section 62 is connected at thedischarge end 63 of the valve which leads into the intake manifold.Under normal operating conditions, the spring 64 urges the valve element65 to the position as shown in Figure 5 wherein the air flow through thevalve element includes a path leading through the side openings 66 andthence around the exterior of the valve element through the annularpassage 67 and on through passage 68 into tubing. 62. A portion of suchair would also travel through the bleed opening 69. Under high vacuumconditions such as are prevalent during idling of the engine the valveelement moves to the right (viewing Figure 5) against the tension of thespring and the conical end face 69 of the valve closes against the valveseat 61 causing the air flow to be confined to passing through thebleed" opening 69. It will be understood that the At the opposite end ofthe regulating valve N, of course, responds automatically to the vacuumcondition within the intake manifold.

When the engine is submerged under water, the overall air route of theventilating system is closed ofi by rotating valve core 15 until link4-6 is engaged with car 43 wherein the valve bores 33 and 34 are movedout of registry with the transfer passages 31 and 32. With thesetransfer passages closed off, the passage 16 leading to theintakemanifold is closed off and there is no air flow through thesystem. The crankcase and passage 19 is likewise closed olf frompassages 18 and 29 (subject to the activity of valve 52). This conditionis only temporary since it is not intended that the engine shouldoperate under water for any extensive period of time. During theoperation of the engine with the valve core 15 closed, a pressurecondition builds up within the crankcase, suflicient to counteract thepressure of the water in which the engine is submerged and therebypreventing entry of water into the interior of the engine. To preventexcessive pressure build up in the crankcase (such as might fracture thevarious sealing gaskets), a relief valve indicated generally by thenumeral 52 is provided and this valve may be in the form of a ball checkvalve wherein the ball 53 is normally seated at the end of passage 54under the tension of spring 55. With transfer passage 31 closed off byvalve core 15, whenever excessive pressure builds up in the crankcase,the ball 53 will be unseated to relieve the excessive pressure and theair can flow through passage 54- and passage 56 and thence out throughtubing section 11 to the air cleaner 1. The passages 54 and 5'6 thuscircumvent the transfer passage 31. The outer end of passage 56 may beclosed off with a threaded plug 57 and a similar threaded plug 58 closesoil the enlarged outer end of passage 54, the diametrically reducedinner end of the plug serving as a pilot and shoulder for the spring andalso serving to limit the travel of the ball 53. It will be understoodthat during operation of the engine under Water, the intake at which theatmospheric air enters the breathing system (herein shown as being theair cleaner 1) is always kept above-the water level.

We have shown our invention as used with a V-type, 4 cylinder engine andit will be understood that in the case of a flat or so-called opposedtype of engine the scavenging of the gases can be via a direct routeleading from the crankcase to the valve M. The reason for this is thatin order to prevent the precision components of the engine from becomingetched by corrosive vapors, it is desirable to vent from the highestpoint in the engine and in a flat type engine a vent from the highestpoint of the crankcase would be sufficient. Thus any corrosive vapors inthe cylinder head covers could be drawn off through suitable passagesformed in the engine block leading to the crankcase or (as in the caseof an engine employing the type of cylinder castings shown herein)through suitable tubes (comparable to tubes 23) leading from thecylinder head covers to the crankcase.

We claim:

1. In a breathing system for an internal combustion engine having an aircleaner, a cylinder head cover, a crankcase, an intake manifold, and acontrol valve, an air route for interconnecting the aforementionedengine parts comprising: a duct leading from the air cleaner to thecontrol valve; a second duct leading from the air cleaner to the valveand being in open communication with the first duct; a duct establishingcommunication between the crankcase and the second air cleaner-to-valveduct via the head cover; an additional duct establishing communicationbetween the intake manifold and the valve, said valve being operable totemporarily close off the air route.

2. In a breathing system for an internal combustion engine having acylinder head cover, a crankcase and an intake manifold: 21 valve bodyhaving several pasasaaseo sages therethrough; a first passage in thevalve body establishing communication between the interior of thecrankcase and atmosphere; an air duct establishing communication betweenthe interior of the crankcase and the cylinder head cover; an additionalair duct establishing communication between the cylinder head cover andthe valve body; a further duct establishing communication between thevalve body and the intake manifold; 21 second passage in the valve bodyfor establishing communication between the last two mentioned ducts anda common valve for closing oil the first and second valve body passages.

3. In a breathing system for an engine having a crankcase and an intakemanifold, an air route for establishing communication between theaforementioned engine parts and including: a branch establishingcommunication between the interior of the crankcase and atmosphere; anadditional branch establishing communication between the interior of thecrankcase and the intake manifold; a common valve interposed in thebranches and operable to close off both branches.

4. In a breathing system for an engine having a crankcase and an intakemanifold, an air route for establishing communication between theaforementioned engine parts and including: a branch establishingcommunication between the interior of the crankcase and atmosphere; anadditional branch establishing communication between the interior of thecrankcase and the intake manifold; a valve body having one passagetherethrough serving one branch and another passage therethrough servingthe additional branch; a valve in the valve body operable tosimultaneously close off the passages in the valve body.

5. In a breathing system for an engine having a crankcase and an intakemanifold, an air route for establishing communication between theaforementioned engine parts and including: a branch establishingcommunication between the interior of the crankcase and atmosphere; anadditional branch establishing communication between the interior of thecrankcase and the intake manifold; valve means for closing off thebranches; additional valve means responsive to pressure for opening: andbleeding oif excess air within one of the branches.

6. In a breathing system for an engine .as set forth in claim 2 whereinthe valve body has a third passage therein for circumventing the commonvalve to establish communication between opposite ends of one of thefirst mentioned valve body passages and a pressure responsive normallyclosed valve operable to open the third passage.

7. In a breathing system for an engine having a cylinder head, acrankcase and an intake manifold, an air route for establishingcommunication between the aforementioned engine parts and including: abranch establishing communication between the interior of the crankcaseand atmosphere; an additional branch establishing communication betweenthe interior of the crankcase and the intake manifold via the cylinderhead cover; a valve body having one passage therethrough servingonebranch and another passage therethrough serving the additionalbranch; said valve body having a bore therethrough which intersects bothof the valve body passages; a valve rotatably received in the bore.

8. In a breathing system for an engine having a crankcase and an intakemanifold, an air route for establishing communication between theaforementioned engine parts and including; a branch establishingcommunication between the interior of the crankcase and atmosphere; anadditional branch establishing communication between the interior of thecrankcase and the intake manifold; a valve in each branch and means forsimultaneously closing the valves.

No references cited.

